Azimuthal decorrelation in tt̄ production at hadron colliders

We present a new observable, Δ an azimuthal angle difference between t and t̄ quarks in tt̄ pair production at hadron colliders as an interesting probe of the radiative quantum chromodynamics process as well as a high-order correction in the high-mass regime. This variable also enables good discrimination on some new physics models that may explain the forward-backward charge asymmetry of tt̄ production measured at the Tevatron. With a reliable estimation of the data set obtained up to 2011 at the Tevatron and Large Hadron Collider, we present an opportunity for testing the standard model as well as searching new physics models with the Δ observable in the lepton+jets decay channel.